Parasitic diseases transmitted by mosquitoes are a major threat to life and health throughout the world. Our ultimate objective is to develop methods for generating strains of vector mosquitoes that are resistent to parasites. These resistent strains of mosquitoes will provide us with tools to study the effects of genetic manipulation on pathogen propagation and transmission. Such strains could be used in novel disease-control strategies that require the release of genetically altered mosquitoes. This Competing Continuation describes experiments that result in the expression of exogenous genes in the salivary glands of the vector mosquito, Aedes aegypti. The specific aims are to 1) define the expression patterns in the salivary glands of female mosquitoes of three reporter genes, chloramphenicol acetyl transferase, beta-galactosidase, and beta-glucuronidase, under control of the Drosophila melanogaster heatshock 70 gene promoter, 2) define the promoters of the genes, D7, encoding the major female salivary gland-specific protein, and Maltase-like 1, in the heterologous and homologous expression systems, and 3) complete the primary characterization of two genes, Amy1 and G12, expressed specifically in the salivary glands. The heterologous assay is the stable transformation of D. melanogaster with hybrid gene constructs composed of a mosquito putative promoter fragment linked to a reporter gene. The homologous expression assay involves microinjection of DNA into mosquito embryos, allowing the mosquitoes to develop to the desired developmental stage, and then assaying for the reporter gene activity. Completion of these experiments will provide techniques for evaluating exogenous gene expression in mosquitoes, a necessary prerequisite to our goal of generating resistant strains.